COMP.7.1
®
TEST INSTRUCTIONS
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Colour Match Method
Using Palintest Comparator
0 – 0.1 mg/l
0 – 2.0 mg/l
0 – 5.0 mg/l
Chlorine and chlorine release compounds are widely used for the disinfection
of water. When dissolved in water chlorine forms hypochlorous acid and
hypochlorite ions. Chlorine remaining in the water in this form is known as
the free chlorine residual.
Chlorine does however react with ammonia and nitrogen-based species to
form chloramines. These compounds are poor disinfectants and can also
impart a characteristic taste or odour to the water. It is important therefore in
certain applications to be able to distinguish between chlorine residual
present as free chlorine and as chloramines.
The Palintest DPD Chlorine/Chloramines method provides a simple means of
measuring free chlorine (HOCI/HOCl ), monochloramine (NH2CI) and
dichloramine (NHCI2).
Method
The Palintest Chlorine/Chloramines test uses the DPD method. This method
is internationally recognised as the standard method of testing for chlorine
and other residuals. In the Palintest method the reagents are provided in
tablet form for maximum convenience and simplicity of use.
Free chlorine reacts with diethyl-p-phenylene diamine (DPD) in buffered
solution to produce a pink coloration. The intensity of the colour is
proportional to the free chlorine concentration. Addition of a trace amount of
potassium iodide induces further reaction with any monochloramine present.
The increase in colour intensity is therefore proportional to the
monochloramine concentration. Subsequent addition of excess potassium
iodide causes dichloramine to react in a similar manner. The increase in
colour intensity is now proportional to the dichloramine concentration.
In this way it is possible to differentiate between free chlorine,
monochloramine and dichloramine residuals present in the sample. The
colour intensities are measured by comparison against colour standards
using a Palintest Comparator and Disc.
Reagents and Equipment
Palintest DPD No 1 Tablets
Palintest DPD No 2 Tablets
Palintest DPD No 3 Tablets
Palintest Comparator (PT 520)
Palintest Comparator Disc CD 011/1, CD011/2 or CD 011/5 Chlorine
Square Test Tubes 13.5 mm, 10 ml (PT 521)
Disc CD 011/1 covers the range 0 - 1 mg/l chlorine in steps 0.1, 0.2, 0.3, 0.4,
0.5, 0.6, 0.7, 0.8 and 1.0 mg/l.
Disc CD 011/2 covers the range 0 - 2.0 mg/l chlorine in steps 0.2, 0.4, 0.6, 0.8,
1.0, 1.2, 1.4, 1.6 and 2.0 mg/l.
Disc CD 011/5 covers the range 0 - 5.0 mg/l chlorine in steps 0.5, 1.0, 1.5, 2.0,
2.5, 3.0, 3.5, 4.0 and 5.0 mg/l.
Test Procedure
1
2
3
4
5
6
7
8
9
Rinse a square test tube with sample leaving two or three drops of sample
in the tube.
Add one DPD No 1 tablet, crush tablet and then fill the test tube with
sample to the 10 ml mark. Mix to dissolve tablet.
Place the test tube in the Comparator and match immediately against disc
in the usual manner (see Comparator instructions).
The disc reading represents the free chlorine residual as mg/l CI2
(Result A).
To measure monochloramine, continue the test on the same test portion.
Add one DPD No 2 tablet, crush and mix to dissolve.
Place the test tube in the Comparator and match against the disc in the
usual manner (Result B) then :Monochloramine (mg/l CI2) = Result B - Result A
To measure dichloramine, continue the test on the same test portion.
Add one DPD No 3 tablet, crush and mix to dissolve.
Allow to stand for two minutes for maximum colour development.
Place the test tube in the Comparator and match against the disc in the
usual manner (Result C) then :Dichloramine (mg/l CI2) = Result C - Result B
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V1-12/03
®
COMP.2.
TEST INSTRUCTIONS
_______________________________________________________________________________________
Colour Match Method
Using Palintest Comparator
0 – 250 mg/l CaCO3
Natural and treated waters may contain a variety of dissolved alkaline
substances such as carbonates, bicarbonates, hydroxides and - to a lesser
extent - borates, phosphates and silicates. In water at neutral pH the
alkalinity derives mainly from the presence of bicarbonates.
Total alkalinity is an important test in determining the aggressiveness or
scale forming tendency of the water. If the total alkalinity is low the water may
be aggressive and cause corrosion to pipework and structures; if the total
alkalinity is high the water may more readily promote scale formation.
Alkalinity control is therefore an important part of many water treatment
programmes.
The Palintest Alkavis test uses a colorimetric method and covers the total
alkalinity range 0 - 250 mg/l CaCO3. The test is particularly suitable for
checking natural and drinking waters, swimming pool water, boiler water, etc.
Method
The Palintest Alkavis test is based on a unique colorimetric method and uses
a single tablet reagent. The test is simply carried out by adding a tablet to a
sample of the water. Under the conditions of the test a distinctive range of
colours from yellow, through green, to blue are produced over the alkalinity
range 0 - 250 mg/l CaCO3. The colour produced in the test is indicative of the
alkalinity of the water and is measured by comparison against colour
standards using a Palintest Comparator and Disc.
CD 192, CM 192, AK 192
Reagents and Equipment
Palintest Alkavis Tablets
Palintest Comparator (PT 520)
Palintest Comparator Disc CD 192 Alkalinity
Square Test Tubes, 13.5 mm, 10 ml (PT 521)
Disc CD 192 covers the range 0 - 250 mg/l alkalinity in steps 0, 25, 50, 75,
100, 125, 150, 200 and 250 mg/l as CaCO3.
Test Procedure
1 Fill a square test tube with sample to the 10 ml mark.
2 Add one Alkavis tablet, crush and mix thoroughly to dissolve.
3 Place the test tube in the Comparator and match against the disc in the
usual manner (see Comparator instructions).
4 The disc reading represents the total alkalinity of the sample as milligrams
per litre CaCO3.
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V1-12/03
®
COMP.27.
TEST INSTRUCTIONS
_______________________________________________________________________________________
Colour Match Method
Using Palintest Comparator
5.2 – 9.6 (4 Ranges)
4 - 11
pH value is a parameter frequently determined on water and aqueous
solutions. The Palintest pH method provides a simple test for the determination
of pH for a variety of applications. The test is available in four narrow ranges
covering pH values between 5.2 and 9.6; and one wide range covering pH
values from 4 to 11.
Method
Palintest pH methods use standard pH indicators in tablet form. Different
indicators are used to cover different pH ranges. Each tablet contains the
precise amount of indicator needed for the test. All Palintest pH tablets
contain a dechlorinating agent so that the tests can be carried out in water
containing chlorine or other disinfectant residuals.
The colour produced when the indicator tablet is added to a sample of the
water is indicative of the pH value. This colour is measured by comparison
against colour standards using a Palintest Comparator and Disc.
CD/CM/AK 128/129/131/135/136
Reagents and Equipment
Palintest pH Indicator Tablets (see table)
Palintest Comparator (PT 520)
Palintest Comparator Disc - pH (see table)
Square Test Tubes, 13.5 mm, 10 ml (PT 521)
Disc Code
CD 128
CD 129
CD 131
CD 135
CD 136
Range of Standards
5.2
6.0
6.8
8.0
4
-
6.8
7.6
8.4
9.6
11
Indicator Tablet Required
Bromocresol Purple
Bromothymol Blue
Phenol Red
Thymol Blue
Universal pH
Test Instructions
1 Select the appropriate disc and indicator tablets for the pH range under
test.
2 Fill a square test tube with sample to the 10 ml mark.
3 Add one pH indicator tablet, crush and mix to dissolve.
4 Place the test tube in the Comparator and match against the disc in the
usual manner (see Comparator instructions).
5 The disc reading represents the pH value of the sample.
Note
If the colour is outside the range of the disc and cannot be matched, the test
should be repeated using a higher or lower range disc with the corresponding
indicator tablets.
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V1-11/03